Hereditary Absence of Spleen in the Mouse

Abstract

THE ‘luxoid’ mutants of the house-mouse form a small and well-defined group with striking limb-defects. In luxate¹ (lx) and luxoid² (lu) homozygotes hind-legs are often twisted, due to reduction or loss of the tibia and distortion of the fibula with associated muscular abnormalities. The femur may also be shortened and fragmented and even the pubic element of the pelvic girdle may be affected in luxates. The hind-feet may show pre-axial poly- or oligo-dactylism, the fore-feet may also be polydactylous in lu lu mice. Heterozygotes may appear normal or may have pre-axial triphalangy or polydactyly of the hind-feet. There are various other skeletal effects (on the number of presacral vertebræ, etc.) while the urogenital system is also involved in luxate homozygotes, with frequent hydronephrosis and hydroureter.